Are you afraid of the dark? "Once upon a time the Moon was always full…" At least, that's what Mug, the old groundskeeper, told Will at camp one day. The summer before seventh grade would forever change the way Will thought about the world, and draw him into an epic struggle that stretched back to the dawn of time. The Moon is in danger, or so Mug says, and only Will is in a position to do something about it. Well... if the bully Rodney doesn't pulverize him first. Can Will choose between his scientific observations and Mug's crazy stories that can't possibly be true, yet feel right? The Moon hangs in the balance between Will's head and his heart. Follow Will and his friends on an adventure on which, of course, all existence is at stake. Wouldn't be fun otherwise, would it?